| 摘要 |
PROBLEM TO BE SOLVED: To always converge onto an optimum focus point with a high focusing precision without depending on an optical disk and the operating environment and to reduce the error rate. SOLUTION: The mechanism adjusts the levels of focus error(FE) signals to an optimum focus point level for an optical disk device. The mechanism is provided with an optical pickup section 1, which reads optical information of an optical disk 2 by illuminating the disk 2 with a light spot, a tracking error(TE) signal detecting section 3, which detects TE signals from the optical information, a bit reproducing(RE) signal detecting section 4, which detects RE signals from the optical information, offset amount adjusting sections 7 and 8, that generate a suitable focus bias voltage corresponding to the intermediate focus offset amount between a first focus offset amount at which the amplitude of the TE signals becomes a maximum and a second focus offset amount at which the amplitude of the RE signals becomes a maximum, and a servo controlling section 9 which focus servo controls the light spot that illuminates the disk 2 using the focus bias voltage that is being superimposed by a suitable focus bias voltage.
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